Month: September 2014

I thought this article “Why Not Space?” deserved to be noted, because it too elucidates the idea of this blog: that space travel is hard, the economics of space travel are not there, the human body is a fragile thing that will struggle to survive very long without massive engineering support.

Ask a random sampling of people if they think we will have colonized space in 500 years, and I expect it will be a while before you run into someone who says it’s unlikely. Our migration from this planet is a seductive vision of the future that has been given almost tangible reality by our entertainment industry. We are attracted to the narrative that our primitive progenitors crawled out of the ocean, just as we’ll crawl off our home planet (en masse) some day.

I’m not going to claim that this vision is false: how could I know that? But I will point out a few of the unappreciated difficulties with this view. The subtext is that space fantasies can prevent us from tackling mundane problems whose denial could result in a backward slide. When driving, fixing your gaze on the gleaming horizon is likely to result in your crashing into a stopped car ahead of you, so that your car is no longer capable of reaching the promised land ahead. We have to pay attention to the stupid stuff right in front of us, as it might well stand between us and a smart future.

and

Space is a hostile place for humans. It’s mostly empty, though not lacking in deadly ionizing radiation and cosmic rays. What few resources exist are so mind-blowingly scattered that they would seem to be utterly absent to the casual observer. Some point out that the open ocean is also hostile to human life, and conjure the image of a luxury ocean liner placidly plying the waters, oblivious to the surrounding harshness. If we can picture that, why is it such a stretch to imagine a luxury liner in space? It’s a gripping image, and would seem to counter worries about the cruelty of space. But let’s look at the oh-so-many ways the two situations cannot compare.

If the ship sinks, and you have a life raft, you stand some chance of rescue. The ocean is vast, but it’s a two-dimensional vastness teeming with human activity (compared to any realistic vision of 3-d space inhabitation even within the confines of our solar system). People have survived for months on the open ocean, subsisting on the elements around them. Running out of air is not a problem. Fresh water falls out of the sky as rain. Critters that are attracted to the cover of your life raft provide a source of food. I recommend the book 117 Days Adrift for a gripping account of a British couple who survived such an ordeal. Sometimes edible fish would actually jump into their dinghy. By contrast, a hamburger has never slammed into the side of the space shuttle in orbit, and I very much doubt that chicken nuggets are going to float up seeking the shelter of your space rescue pod!

The rest of the article is a fascinating read from a space scientist, no less.

This post is the first of many, many posts on the human exploration of Mars.

Why we can’t get there from here

I have great sympathy for the principle of human exploration of Mars and even potential colonization in the future. But frankly the belief that we can transport humans to Mars, have them land safely, conduct experiments and exploration and safely return using current or near future technologies is rooted in a quasi-religious belief system which I call “hard science fiction” and is the meta-theme of this blog.

Now this article isn’t saying that getting to Mars is impossible, but in reality things can go wrong (just ask the crew of Apollo 13) and aborting a mission to Mars is one of the things that needs to be considered.

I love the question posed (by someone called Joan):

Could Mars One turn back en route if they had regrets? Reality would set in seeing[our] beautiful blue planet get smaller while they head towards a dead toxic planet or if radiation/solar winds [were] to wildly [exceed] safe levels.

Now that’s a question that needs to be answered.

Not because crews might have regrets, because that’s what an astronaut training program would be geared to filter out, because the last thing you’d want is a crew member who goes into a psychotic fit en route to Mars and must be (physically and/or chemically) restrained. In a module as small and claustrophobic as a Mars module, that would cause a mission abort all on its own.

But Mars is (as far as we know) dead and is definitely toxic, so this is not a trivial question.

…when we talk about a manned mission to Mars, there are a few different plans out there. The most optimal one for a one-way trip to Mars, for those of you wondering, that minimizes both flight time and the amount of energy needed, involves simply timing your launch right.

There’s an approximately two-month-long launch window that occurs every 780 days, where Earth overtakes Mars in its orbit, where the time-of-flight to Mars is only about 243 days: 8½ months. The tough part is, once you’re on your way, you’re moving at incredible speeds, and you’re not carrying a lot of fuel on board to correct your trajectory.

Why not?

Because every extra kilogram of fuel you carry means it’s that much more expensive to launch your rocket, and it also means there’s that much less storage room and capacity to devote to food, water and other supplies. As a consequence, there’s that much less room-for-error. If the infamous Apollo 13 mission hadn’t planned on landing on the Moon, lifting off to reconnect with the command module, and return to Earth, they never would have had enough fuel to make the necessary course corrections to get themselves back home.

That optimal strategy is called the Hohmann Transfer which is the one diagrammed above, and every other option sub-optimal because it would require more fuel and hence more mass would have to be sent up from the Earth’s surface in the first place.

If you’re on your way to Mars, and you all-of-a-sudden decide you have to get back to Earth, using your on-board fuel to change your course and head back home simply wouldn’t be an option: fuel-wise, it’s too expensive. In other words, Joan, to answer one of your questions, if it was radiation that was killing you — something we may have to worry about, as we’ve never had humans spend large amounts of time this far away from Earth’s protective magnetic field — you’re simply going to die.

So, once you’ve broken Earth’s orbit at the beginning of the Hohmann transfer then you’re committed – you won’t have enough fuel to turn around the way they do in the movies.

But if time wasn’t an issue, because you had the food, water and supplies you needed to survive, and you had all the fuel you needed to get yourself to Mars, you’d have a chance to return home. This could be of vital importance for a mission like the one you allude to — Mars One — because the way it’s currently planned, it’s a suicide mission.

And it is – right up front, Mars One is a one-way trip to a dead, toxic planet. Once you’re on that transfer, you’ll never see Earth again.

Unless you’re in just the right orbit where this happens:

So if you were on your way to Mars and wanted to come back, your only realistic option, with the expected amount of fuel you’d outfit your spacecraft with, would be to use the red planet’s gravity to turn yourself around back towards Earth, which would result in a total round-trip time of around 400-to-450 days. Without any interplanetary infrastructure, that’s the best you can hope for.

But all of the above rests upon a key assumption – that there is no infrastructure on Mars.

Why would that be the case?

Mars Direct

In Robert Zubrin’s book “The Case for Mars”, he advocates a mission strategy called “Mars Direct” which envisages a series of missions to colonize, explore and return samples (and humans) from the surface of the planet.

The first mission, which Zubrin dubs “Ares 1”, a robotic mission is sent first which sends a habitation module, a nuclear power plant, a chemical plant and a return vehicle to Mars.

The whole lot lands on Mars (a heroic assumption, given the poor record of Mars landers), where the chemical plant uses water in the soil of Mars which is heated by the nuclear power plant and then cracked into hydrogen and oxygen, which are then used to fuel the return vehicle and the habitation module (the “Hab”).

Then when all is signalled ready by the robotic Ares 1, the human part (“Ares 2”) lifts off, knowing that at the very least, the astronauts can abort either directly as shown above, or to the surface of Mars.

There’s at least one problem with that strategy: we don’t have the technology to land humans safely on Mars

Western popular culture is saturated with science fiction. Some science fiction is presented as fiction, some as fact, and most of the time somewhere between those two extremes.

Sometimes the science part of science fiction is used to generate a different view on what society could become given different circumstances. So the science given is a literary device used to suspend belief and take the reader or viewer on an imaginary journey.

Sometime science fiction is generated by people we would call scientists, and is used deceitfully to gain honour and prestige within the scientific community and beyond.

Sometimes scientific concepts are abused to the point of nonsense by people claiming some deeper insight into the Universe.

And there are shades, genres and fashions linking all of the above.

Don’t get me wrong about this. Having been born in the middle of the Space Race and seen men walking on the Moon, I’ve seen science fiction become science fact.

Science fiction in popular culture has many forms, such as space opera like Star Trek, Star Wars, Space 1999 and Babylon 5, or supposed harder science fiction such as Armageddon, I Robot or Blade Runner.

But the hard sciences underpinned by the universal language and toolkit of mathematics are not about what is possible. They are about what is not possible.

For example, perpetual motion machines are not possible, but it hasn’t stopped lots of people trying and claiming that this or that conceptual design produces more energy than is input. Sometimes this comes out of genuine misunderstanding about scientific concepts, but more often it is by conscious fraud.

So this blog is about science and what is possible and what is not.

But that doesn’t mean that people, like the Red Queen, cannot believe six impossible things before breakfast.